Connector and method for establishing solderfree connections between a rigid main PCB and associated conductors

ABSTRACT

A compact connection assembly and a method for establishing solderfree electrical connections between a main PCB and associated conductors e.g. arranged on a flexible foil strip or on a flexible PCB. The connection assembly is particularly suitable for use in compact electronic equipment such as hearing instruments or mobile phones where one can benefit from the small dimensions obtainable by the described connection assembly.

FIELD OF THE INVENTION

The present invention relates to a connection assembly and a connectionmethod providing solderfree electrical connections between a number ofconductors disposed on a main printed circuit board (main PCB) andassociated conductors arranged on e.g. a flexible foil strip or on aflexible PCB. The present invention is particularly well adapted for usein compact electronic equipment such as hearing instruments or mobilephones where one can benefit from the small dimensions obtainable by thepresent connection assembly.

BACKGROUND OF THE INVENTION

Electronic equipment, such as hearing instruments, mobile phones,medical dispensing devices etc., may require that a number of electricalconnections is established between a main PCB and various parts of theequipment, such as electro-acoustic transducers, LCD displays,keyboards, user operated switches and contacts etc. These electricalconnections may operate to provide DC voltages and currents, digitaldata signals, transducer signals etc., from the main PCB to theperipheral units or vice versa.

Each of these parts, from now on referred to as peripheral units,typically comprises a number of electrical terminals which is used toestablish the electrical connections to the main PCB and/or a ceramichybrid circuit provided with corresponding electrical contact pads orterminals.

For hearing instrument applications, peripheral units such asmicrophone(s), receivers, telecoils etc. are required for audio signalreception and amplification as well as magnetic field reception andamplification.

Furthermore, hearing instruments may also require switches, contacts andprogramming plugs which are used for a variety of purposes such asturning a battery supply on/off, adjusting the volume, programming ofinstruments, changing between several pre-programmed listening programsor changing between a microphone and a telecoil audio signal, etc.

The signals provided to or from these peripheral units may comprisesignals in a digital or analogue form. A digital signal may represent alogic state or a change of a logic state of a switch, such as a programselector switch, or it may represent digitally encoded analoguetransducer signals provided to/from the microphones, receivers etc.

The main PCB of a hearing instrument typically comprises one or severalintegrated circuits and associated passive components to performprocessing and storing of audio or control signals generated by theperipheral units.

Depending on the type of peripheral unit, it may require that two, threeor even more terminals are electrically connected to the main PCB. Theseconnections are often provided by means of flexible leads, such as wellknown litz wires, each lead having a first end soldered at the terminalof the peripheral unit, and having a second end soldered to thecorresponding pad or terminal on the main PCB. To ensure that each ofthese connections is properly made during manufacture or repair of thehearing instrument, several litz wires of differing colour are oftenprovided so that a particular transducer terminal and its correspondingcontact pad on the main PCB are associated with a particular wirecolour.

Several drawbacks exist in this well-known method of establishing theelectrical connections by use of flexible leads between the terminals ofthe peripheral unit and the pads located on the main PCB.

A first drawback relates to the soldering itself. Since the peripheralunits must, generally, be miniature for use in today's in-the-canal(ITC) and compact behind the ear (BTE) types of hearing instruments, theheat capacity of each of the terminals is, inherently, very small. Thesmall heat capacity requires very strict monitoring of solderingtemperature and soldering time to avoid overheating the terminals, whichin worst case could destroy the operation of the peripheral unit, or atleast severely damage the reliability. Furthermore, transducers areoften provided with integrated circuits within their housings or casingsand these integrated circuits are electrically and thermally connectedto the transducer terminals. Consequently, overheating these transducerterminals may conduct sufficient heat to the integrated circuits to meltbonding wires and/or overheat the integrated circuits themselves.Obviously, similar soldering related problems also exist duringsoldering on the contact or connection pads arranged on the main PCB ofa hearing instrument or of another compact electronic device.

Accordingly, overheating transducer or switch terminals is a seriousproblem, particularly during service in repair shops but also duringfactory assembly of the hearing instruments.

A second drawback related to the use of the flexible leads to providethe required electrical connections between the peripheral units and aPCB of e.g. a hearing instrument is that an operator may need to findand consult a wiring diagram in e.g. a repair manual to determine thecorrect connection pad for a given wire.

In some situations, the widespread use of litz wires as electrical leadsmay generate problems in the hearing instrument assembly or repairprocess, since this type of wire is prone to mechanical damage thatoften results in detachment of noninsulated strands of wires from thewire core. These strands may establish unintended connections tocircuitry and/or terminals within the hearing instrument, and thus leavethe hearing instrument in a non-operational state.

Another drawback of using flexible leads is that the leads are unsuitedfor automated machine assembly. Consequently, human operators arerequired to carry out the process of soldering and correctly connectingthe leads between corresponding terminals or pads on the peripheral unitand on the main PCB.

Accordingly, it would be desirable to provide a method which is capableof establishing solderfree electrical connections between the terminalsof a peripheral unit and connection pads of a PCB of an electronicdevice or apparatus, such as a hearing instrument, a mobile phone, amedical dispensing apparatus etc. Likewise, it would also be desirableto provide a, preferably compact, connection assembly adapted forutilisation in such a connection method.

U.S. Pat. No. 4,116,517 discloses a connection assembly providingsolderfree electrical connections between a number of hollow contactpads arranged on a flexible circuit board or strip, and a correspondingnumber of exposed metallic pads or traces on a PCB. The hollow contactpoints on the flexible circuit strip are filled with an elastomericmaterial, thereby forcing these contact points against the pads on thePCB. Screws and nuts are used to keep the two boards properly alignedand the pads in electrical contact.

DE 41 36 204 A1 discloses a method of providing solderfree electricalconnection between a number of conductors in flexible ribbon cable and acorresponding number of exposed metallic pads on a PCB. The contactpoints of the PCB and ribbon cable are kept in electrical contact by aclamping element secured by screws and nuts to the PCB.

However, these prior-art methods of providing solderfree electricalconnections share a common drawback due to their requirement ofallocating a significant area of the PCB to the screws and nuts.Furthermore, the assembling and fastening procedure required for thescrews and nuts may require manual operation steps which are timeconsuming and therefore adds to the cost of an apparatus utilising suchmethods. Within housings of miniature electronic equipment such ashearing instruments, the space required to handle or operate tools forassembling the screws and nuts may not be available. Consequently, noneof these connectors and connection methods are fully suitable forapplication in miniature or compact electronic equipment.

SUMMARY OF THE INVENTION

It is an object of the present invention to solve the above-mentionedproblems by providing a compact connection assembly establishing asolderfree electrical connections between a peripheral unit and a PCB ofan electronic apparatus, such as a hearing instrument, a mobile phone, amedical dispensing device, or other electronic equipment.

It is a further object of the present invention to provide a connectionassembly that operates without using screws and nuts so as to avoid theabove mentioned drawbacks of these elements.

It is a still further object of the present invention to solve theproblems associated with soldering on the terminals of the peripheralunits by providing a connection assembly comprising a peripheral unitwhich is integrated with the flexible printed circuit strip or flexiblefoil strip.

Furthermore, problems related to the use of flexible leads, such as litzwires, can be solved by one embodiment of the present invention whereinleads are replaced with a flexible printed circuit strip or flexiblefoil strip comprising two or more electrical conductors.

In a first aspect, the present invention relates to a connectionassembly being adapted to maintain electrically conducting contact padsof a PCB and exposed parts of a member in a predetermined alignment,said connection assembly comprising a U-shaped clamp comprising two legparts and a back part, wherein the back part of the clamp comprises anaperture being adapted to receive a first end of the member, and whereinthe leg parts of the clamp are positioned with a predetermined spacingso as to obtain electrical contact between the contact pads of the PCBand the exposed parts of the member when the contact pads and theexposed parts are aligned with respect to each other.

The term “clamp” is to be understood in a broad sense in the presentcontext. Thus, “clamp” may designate various devices having two legparts and a back part and that are capable of applying a force betweenthe member and the PCB, thereby clamping together the contact pads andthe exposed parts. The embodiment of the clamp shown in FIG. 1 alsopossess functional features similar to those of a bushing, e.g. theaperture in the back part allowing insertion of the member.

Each of a number of electrical signals may be provided on acorresponding electrical conductor, which is comprised within ordisposed on the member that may be a flexible foil strip or a strip offlexible PCB. These conductors may be covered by an insulating mask,which protects them from corrosion and physical damage. In order toprovide an electrical connection pad to the conductor, an exposed partmay be provided by forming an aperture in the insulating mask of eachconductor at the first end of the member. By forming a number of alignedapertures a number of exposed parts acting as connection pads orterminals is provided on the member. These connection pads are typicallyformed only on one side of the member while the conductors on other sidemay be rendered completely covered by the insulating mask.

The member may be inserted into an aperture provided in the back part ofthe U-shaped clamp by an operator. The exposed parts will be alignedwith respect to the corresponding electrically conducting contact padsarranged on the main PCB. After the pads have been correctly aligned,the member may be positioned on top of the PCB and the two items may beclamped together so that electrical connection is established between acontact pad and a corresponding exposed part. Subsequently, by slidingthe clamp along the member towards the main PCB, the clamp may bepositioned with the first leg part on top of the member, and the secondleg part on the backside of the main PCB. The predetermined spacingbetween the leg parts of the clamp is chosen so that the U-shaped clampprovides a predetermined spring force between the main PCB and themember, thereby clamping them together. Accordingly, a predeterminedcontact force is established between the exposed parts on the member andthe contact pads on the main PCB. The value of this contact force isselected according to the dimensions of the connection assembly andadditional requirements specific for the particular application inquestion.

A U-shaped clamp adapted for hearing instrument applications may havedimensions of about 1-5 mm and the provided contact force is,preferably, selected in the range 0.2-2.0 Newton, preferably between0.5-1.0 Newton for each pair of contact elements constituted by acontact pad and its corresponding exposed part.

Correct alignment between the pairs of corresponding contact elementsmay be provided and secured in a number of ways.

According to one embodiment of the invention, one of the leg parts ofthe U-shaped clamp comprises a central groove and two outer partsextending from the back part aperture towards the end of the leg part,whereby the predetermined spacing exists between the central part andthe other leg part. This central groove may be manufactured with a widthsubstantially equal to a width of a flexible foil strip that mayconstitute the member. Thereby the flexible foil strip may be steered orguided in a predetermined alignment with respect to the clamp,consequently, the contact pads arranged on the main PCB and the exposedparts provided on the flexible foil follow this steering.

According to another embodiment, the aperture in the U-shaped clamp hasa width substantially equal to the width of the member. Thereby, theexposed parts of the member may be aligned in a predetermined mannerwith respect to the U-shaped clamp. The dimensions of the aperture areadapted to the width of the member so that during mounting of theconnection assembly, the aperture aligns the member when insertedin/through the aperture in the back part of the clamp. Consequently,this embodiment facilitates correct alignment of the exposed parts onthe member with respect to the corresponding contact pads on the mainPCB.

As detailed above, several methods exist for aligning the membercorrectly with respect to the U-shaped clamp, it is, however, alsonecessary to resolve the problem of how to correctly align the U-shapedclamp and the main PCB with respect to each other. According to oneembodiment, this alignment may be established by providing a set ofcorresponding engaging means, a first engaging means provided on the PCBand a second engaging means provided on a leg part of the U-shapedclamp, whereby the contact pads and the exposed parts may be alignedwith respect to each other when the set of engaging means are engaged.

Accordingly, either the upper and/or lower surface of the PCB may beprovided with a groove or an indentation preferably extendingsubstantially in a parallel or perpendicular direction to the edgecontour of the main PCB. Similarly, the upper and/or lower leg part ofthe clamp may comprise a corresponding projection(s) adapted to engagewith the groove or indentation. Naturally, different sets ofcorresponding engaging means may also be utilised for alignment, one orseveral pins on one of the leg parts of the clamp may engage with acorresponding aperture(s) provided on the main PCB.

According to a preferred embodiment of the invention, the alignment isprovided by a projection comprised on an inner surface of a leg part ofthe U-shaped clamp and by providing the conducting contact pads asplated thru-holes forming an indentation being adapted to engage withthe projection so as to provide a snap-connection between the clamp andthe PCB. Accordingly, the plated thru-holes may function as anindentation arranged on an upper surface of the main PCB and may extendin a direction substantially parallel to an edge contour of the PCB. Theupper leg part of the clamp may in this situation comprise a projectionadapted to engage with the indentation formed by the plated thru-holes.This embodiment has the advantage that the plated thru-holes serve adouble purpose—they provide an alignment indentation enabling thesnap-connection and they provide the conducting contact pads required toestablish the electrical connection to the conductors of the main PCB.Furthermore, the plated thru holes may be manufactured during alreadyexisting processing steps of the main PCB, i.e. they do not require newprocess steps to be added to the manufacturing process.

According to a preferred embodiment of the invention, the correctalignment of the U-shaped clamp with respect to the main PCB is providedby manufacturing the main PCB with an indentation of substantially samewidth as the width of the U-shaped clamp. Accordingly, when the clamp isinserted into this indentation after the member has been inserted intothe back part aperture of the clamp, the clamp is correctly aligned withrespect to the main PCB and the exposed parts on the member arecorrectly aligned with respect to the corresponding contact padsprovided on the main PCB. Thus, when the clamp slides forward so as toengage with the main PCB and clamp together the member and the PCB, theprojection that may be comprised on the upper leg part will snap ontothe corresponding indentation formed by the plated thru-holes providedon the main PCB, thereby locking the position of the exposed parts onthe member correctly relative to the corresponding contact pads on thePCB.

Preferably, the depth of the U-shaped clamp is adapted to the dimensionsof the indentation in the circuit board so as to substantially align theback part of the clamp with the edge contour of the PCB when the contactpads and the exposed parts are aligned with respect to each other.

According to one embodiment of the invention, at least one of the legparts of the U-shaped clamp comprises means for receiving an operatorsnail, thereby enabling disassembly of the connection assembly by anoperator/technician without use of specialised tools, such as miniaturescrewdrivers, tweezers etc.

The U-shaped clamp may be manufactured in stainless steel or in athermoplastic material with or without reinforcement. In someapplications it may be advantageous to use a clamp of a thermoplasticmaterial due to its electrically insulating properties. This could bethe situation where the member was provided with exposed conductors onthe backside (the side reverse to the side comprising the exposedparts). In other applications, the conductors on the backside could becovered with an insulating mask and, accordingly, the clamp may beprovided in stainless steel. Stainless steel may be advantageous forsome applications due to its high strength, whereby a required clampingforce may be provided by a clamp of small dimensions.

In this context it should be noted that the predetermined spacingbetween the leg parts and the clamp material must be selected so thatthe contact force acting upon the member and the main PCB meets therequirements of the particular application. The requirements to thecontact force may depend on the mechanical stress level acting on theconnection assembly due to factors such as structural vibrations andbending forces. A connection assembly adapted to hearing instrumentapplications has, preferably, outer dimensions of about 1-5 mm and apredetermined spacing between the leg parts of about 0.1-1.0 mm, morepreferably between 0.3 and 0.6 mm. Thereby, a contact force of about0,1-1.0 Newton for each pair of corresponding pads and exposed parts maybe generated through appropriate selection of material.

The member may comprise a flexible printed circuit strip or board or aflexible foil strip or any other suitable carrier adaptable to compriseone or several electrical conductors. Alternatively, the member maycomprise a flexible ribbon cable where the exposed parts could be formedby removing the insulating material from each conductor at one end ofthe ribbon cable.

According to a preferred embodiment of the invention, a second end ofthe member is electrically connected to, or integrated with, anelectro-acoustic transducer, a switch or a potentiometer. Thisembodiment is particularly suitable for hearing instrument applications,since a technician may replace a defective peripheral unit withouthaving to solder inside the hearing instrument housing or on thetransducer terminals. The skilled person will appreciate that this is amajor advantage provided by the present invention, since the previouslymentioned hazards of soldering on transducer terminals or on the contactpads of the main PCB within a hearing instrument casing are eliminated.

Furthermore, this embodiment additionally provides the advantage ofproviding a convenient and solderfree method of replacing one type ofperipheral unit with different types whereby acoustical propertiesand/or functional features of a hearing instrument may be customised tothe wishes and/or requirements of a particular hearing instrument user.

In a second aspect, the present invention relates to a method ofproviding solderfree electrical connections between pairs ofcorresponding electrical terminals, the method comprising the steps of:

providing a PCB having at least two conductors disposed on a surfacethereof, each conductor comprising an electrically conducting contactpad,

providing a member comprising at least two conductors, each conductorhaving an exposed part at a first end of the member,

providing a U-shaped clamp comprising two leg parts and a back part, theback part comprising an aperture which is adapted to receive the firstend of the member, the two leg parts being separated with apredetermined spacing,

inserting the member into the aperture in the back part and positioningpairs of the corresponding contact pads and exposed parts in alignment,and

sliding the clamp along the member towards the PCB until the clamp ispositioned with the first leg part on top of the member, and the secondleg part abutting the backside of the PCB.

Accordingly, the second aspect of the invention relates to a method ofestablishing solderfree electrical connections between conductorsarranged on e.g. a PCB and corresponding conductors comprised on e.g. aflexible PCB. The method utilises a U-shaped clamp which is adapted toclamp together the PCB and the member. The method avoids the use ofscrews and nuts or similar fastening and/or engaging means whichtypically occupy significant area of PCBs as well as housing volume.Accordingly, the method is particularly well suited for applications inelectronic equipment where it is a key requirement to minimise the useof PCB area and the use of interior housing volume. Such requirementsoften prevail within compact electronic equipment, such as hearinginstruments, mobile phones, medical dispensing devices, etc.

The method according to the second aspect may further comprise the stepsof

providing exposed parts having a length in the longitudinal direction ofthe member longer than the length of each corresponding contact pad,

positioning the pairs of corresponding contact pads and exposed parts inwidth-wise alignment, and

removing a residual part of the member extending longitudinally acrossan upper surface of the PCB.

The width-wise direction is in this context the direction substantiallyperpendicular to the longitudinal direction of the member and to theconductors of the member.

The advantage of this method is that there is less strict requirementsregarding the longitudinal direction alignment of the pairs ofcorresponding contact pads and exposed parts since the exposed parts maybe provided with a length of 1-10 times the length of the contact pads,preferably 1.5-6 times the length of the contact pads, even morepreferably between 2 and 4 times the length of the contact pads.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereunder, a preferred embodiment of an a connection assembly accordingto the invention is described with reference to the drawing, wherein

FIG. 1 is a perspective view illustrating the parts comprised in theelectromechanical encoder according to the present invention.

FIGS. 2A-2E illustrate the method according to the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

FIG. 1 shows a perspective view of a connection assembly according tothe present invention and adapted for use in BTE, ITC and CIC types ofhearing instruments. The connection assembly comprises a main PCB 1within a hearing instrument housing (not shown). Five plated thru holes30 are arranged on the upper surface of the main PCB 1 and extend in adirection substantially parallel to the edge contour 10 of the PCB 1 sothat an indentation is formed in the surface of the main PCB 1. An upperleg part 15 of a U-shaped clamp 35 comprises a projection 40 adapted toengage with the indentation formed by the plated thru holes 30. Apredetermined spacing exists between the upper leg part 15 and the lowerleg part 45 of the clamp. Receivers 25 are adapted to receive anoperator's nail. The receivers 25 protrude from at least one of the legparts of the U-shaped clamp e.g. the upper leg part 15, thereby makingit easier to disengage the clamp 35 such that said clamp may be removedfrom an indentation 5.

This spacing is preferably about 0.3-0.6 mm when the nominal thicknessof the main PCB is about 0.3 mm and the nominal thickness of a flexiblecircuit board 2 is about 0.1 mm. Preferred dimensions of the clamp inthe present embodiment are: depth=0.8 mm, width=0.7 mm.

The back part of the clamp 35 comprises an aperture 20 having a widthsubstantially equal to the width of the flexible circuit board 2 so thatthe aperture aligns the flexible circuit board 2 with respect to theclamp 35 when the flexible circuit board 2 has been inserted through theaperture 20 in the back part of the clamp.

The clamp is, preferably, provided in a thermoplastic material since alow cost injection moulding manufacturing process may then be utilised.

FIGS. 2A-2E illustrate the method of the preset invention wherein FIGS.2A-2C illustrate the PCB 1, the flexible circuit board 2 (includingexposed part 22), and the clamp 35, respectively. In FIG. 2D, theflexible circuit board 2 in inserted in the aperture 20 of the clamp 35,and in FIG. 2E, the clamp 35 is slid along the flexible circuit board 2toward the PCB 1 until the clamp 35 is positioned with the upper legpart 15 on top of the flexible circuit board 2 and the lower leg part 45abutting the backside of the PCB 1, and so that the projection 40engages the through hole 30.

What is claimed is:
 1. A connection assembly being adapted to maintain aPCB's electrically conducting contact pads, provided as platedthru-holes forming grooves, and exposed parts of a member in apredetermined alignment, said connection assembly comprising: a U-shapedclamp manufactured in one piece in a thermoplastic and resilientmaterial and comprising two leg parts and a back part, wherein the backpart of the clamp comprises an aperture being adapted to receive a firstend of the member, and wherein the leg parts of the clamp are positionedwith a predetermined spacing so as to obtain electrical contact betweenthe contact pads of the PCB and the exposed parts of the member when thecontact pads and the exposed parts are aligned with respect to eachother, and wherein an inner surface of one of the leg parts comprises aprojection being adapted to engage with a groove so as to provide asnap-connection between the clamp and the PCB; and wherein thesnap-connection provides a physical connection between the clamp and thePCB.
 2. A connection assembly according to claim 1, wherein one of theleg parts comprises a central groove and two outer parts extending fromthe back part aperture towards the end of the leg part.
 3. A connectionassembly according to claim 1, wherein the aperture in the U-shapedclamp has a width substantially equal to a width of the member, therebyaligning the contact pads and the exposed parts with respect to eachother.
 4. A connection assembly according to claim 1, wherein the PCBand a leg part of the U-shaped clamp comprises engaging means beingadapted to align the contact pads and the exposed parts with respect toeach other.
 5. A connection assembly according to claim 1, wherein atleast one of the leg parts of the U-shaped clamp comprises means forreceiving an operators nail.
 6. A connection assembly according to claim1, wherein the member comprises a flexible printed circuit strip orboard.
 7. A connection assembly according to claim 1, wherein the membercomprises a flexible foil strip.
 8. A connection assembly according toclaim 1, wherein a second end of the member is electrically connectedto, or integrated with, an electro-acoustic transducer, a switch or apotentiometer.
 9. A connection assembly according to claim 1, whereinthe assembly is utilised in a hearing instrument or a telecommunicationunit, such as a mobile telephone.
 10. A connection assembly according toclaim 1, wherein a largest dimension of the clamp is less than 5 mm. 11.A connection assembly according to claim 1, wherein the predeterminedspacing between the leg parts is between 0.1 and 1.0 mm.
 12. Aconnection assembly according to claim 1, wherein the PCS is providedwith an indentation of substantially a same width as the width of theU-shaped clamp.
 13. A connection assembly according to claim 12, whereinthe back part of the U-shaped clamp has a thickness substantially equalto a depth of the indentation in the PCB so as to align the back part ofthe clamp with the contour of the PCB.
 14. A method of providingsolderfee electrical connections between pairs of correspondingelectrical terminals, the method comprising the steps of: providing aPCB having at least two conductors disposed on a surface thereof, eachconductor comprising an electrically conducting contact pad provided asa plated thru hole forming a groove, providing a member comprising atleast two conductors, each conductor having an exposed part at a firstend of the member, providing a U-shaped clamp made in one piece of athermoplastic and resilient material and comprising a first and a secondleg part and a back part, the back part comprising an aperture which isadapted to receive the first end of the member, the two leg parts beingseparated with a predetermined spacing, an inner surface of one of theleg parts comprising a projection adapted to engage with a groove so asto provide a snap-connection between the clamp and the PCB, insertingthe member into the aperture in the back part and positioning pairs ofthe corresponding contact pads and exposed parts in alignment, andsliding the clamp along the member towards the PCB until the clamp ispositioned with the first leg part on top of the member, and the secondleg part abutting the backside of the PCB, and so that said projectionengages said groove; wherein an interaction between said projection andsaid grove provides a physical connection between the clamp and the PCB.15. A method according to claim 14, further comprising the steps ofproviding exposed parts having a length in the longitudinal direction ofthe member longer than the length of each corresponding contact pad,positioning the pairs of corresponding contact pads and exposed parts inwidth-wise alignment, and removing a residual part of the memberextending longitudinally across an upper surface of the PCB.
 16. Aconnection assembly comprising: a U-shaped clamp manufactured in onepiece in a thermoplastic and resilient material and comprising two legparts, a back part, and at least one protrusion wherein the back part ofthe clamp includes an aperture being adapted to receive a first end of amember, and wherein the leg parts of the clamp are positioned with apredetermined spacing so as to obtain electrical contact between contactpads of a PCB and exposed parts of the member when the contact pads andthe exposed parts are aligned with respect to each other; wherein aninner surface of one of the leg parts includes a projection beingadapted to engage with a groove so as to provide a snap-connectionbetween the clamp and the PCB; and wherein the at least one protrusionis operable by an operator's fingernail to disassemble the clamp and thePCB.
 17. A connection assembly according to claim 16, wherein the atleast one protrusion includes two protrusions.
 18. A connection assemblyaccording to claim 16, wherein the at least one protrusion extends fromone of the leg parts.
 19. A connection assembly according to claim 16,wherein the at least one protrusion extends in a direction substantiallyparallel to an edge contour of the PCB.
 20. A connection assemblyaccording to claim 16, wherein the at least one protrusion is curved.21. A method of disassembling a connection assembly including a PCBhaving at least two conductors disposed on a surface thereof, eachconductor including an electrically conducting contact pad provided as aplated through hole forming a groove, a member including at least twoconductors, each conductor having an exposed part at a first end of themember, and a U-shaped clamp, made in one piece of a thermoplastic andresilient material and including a first and a second leg part, a backpart, and at least one protrusion wherein the back part of the clampincludes an aperture being adapted to receive a first end of the member,and wherein the leg parts of the clamp are positioned with apredetermined spacing so as to obtain electrical contact between thecontact pads of the PCB and exposed parts of the member when the contactpads and the exposed parts are aligned with respect to each other,wherein an inner surface of one of the leg parts includes a projectionbeing adapted to engage with a groove so as to provide a snap-connectionbetween the clamp and the PCB, said method comprising: operating the atleast one protrusion to disassemble the clamp and the PCB.
 22. A methodaccording to claim 21, wherein the at least one protrusion is operatedby an operator's fingernail.
 23. A connection assembly according toclaim 21, wherein the at least one protrusion includes two protrusions.24. A connection assembly according to claim 21, wherein the at leastone protrusion extends from one of the leg parts.
 25. A connectionassembly according to claim 21, wherein the at least one protrusionextends in a direction substantially parallel to an edge contour of thePCB.
 26. A connection assembly according to claim 21, wherein the atleast one protrusion is curved.